1.1 PHYSIOLOGY - Cellular Physio Flashcards
Ability to maintain stable internal environment.
Homeostasis
Define physiology.
Explains the physical and chemical factors that are responsible for the origin, development, and progression of life.
Arterial O2 partial pressure
100 mmhg
Arterial CO2 partial pressure
40mmhg
Typical GFR
125ml/min
Typical value of setum Ca2+
2.4 meq/L
Which is more common? Negative or positive feedback control?
Negative
2 parts of the cell cycle
Interphase and mitosis
Parts of interphase
G1
DNA synthesis
G2
Mitosis typically lasts for
30 mins
Parts of mitosis
Prophase, prometaphase, metaphase, anaphase, telophase
Mnemonic PPMAT
Name which part of mitosis is described.
Condensation of chromosomes and formation of mitotic spindle
Prophase
What happens in prometaphase?
Aster fragments the nuclear envelope and attaches to the centromere
Sister chromatids pulled towards opposite poles
What happens in metaphase?
Two asters are pushed further apart
Chromatids line up to form the equatorial plane
What happens in anaphase?
Chromatids are pulled apart at the centromere tords opposite poles
What happens in telophase?
New nuclear membrane develops, mitotic spindle dissolute, cell pinches into two
Cell classification according to membrane bound organelles
Prokaryotes and Eukaryotes
Cell classification according to the ability to reproduce
Labile, Quiescent/Stable, Permanent/Non-dividing
Examples of labile cells
Hematopoeitic cells, skin (spontaneous production)
Example of quiescent cells
Intestine, liver cells (do not reproduce but can if prompted)
Substance that makes up the cell
Protoplasm
Examples of permament or non-dividing cells
Neuron, skeletal, cardiac muscle (do not reproduce)
Water is not present in adipose tissue. True or false.
True
Composition of the protoplasm
Water 70-80% Proteins 10-20% Lipids 2% Ions Carbohydrates
Almost all nucleated cells in the body contain the SAME set of chromosomes and DNA except
Lymphocytes which undergo genetic rearrangement
Powerhouse of the cell
Forms ATP
Mitochondria
Parts of the mitichondria
Outer membrane
Intermembranous space
Inner membrane
Mitochondrial matrix
Organelle that contains its own DNA
Mitochondria
Start codon
AUG
Other name for smooth ER
Agranular ER
Genetic material from the mitochondria is purely
Maternally-derived
SERs are abundant in which organs?
Liver, kidney cells, testes, ovaries, adrenal cortex
Function of the SER
Mr clean of the cell (smooth, panlaba, mataba)
Involved in DETOXIFICATION
Synthesis of lipids and contains glycogenolytic enzymes
Other name for Rough ER
Granular ER
Function of the RER
Protein factory of the cell
RER contains ribosomes
RERs are abundant in which organs
Liver, neurons, pancreas, thyroid
2 types of ribosomes
RER vs free floating
Ribosomes bound to the RER are found in the
Cell membrane
Lysosomes
Any proteins secreted out of the cell (hormones, neurotransmitters)
Free floating ribosomes are found in the
Cytoplasm and mitochondria
The SER in skeletal muscles and the RER in the neuron are called?
Sarcoplasmic reticulum/Nissl substance
Packaging department of the cell
Golgi apparatus
Functions of the Golgi apparatus
Packaging
Molecular tagging
Synthesis of hyaluronic acid and chondroitin sulfate
Structure of the Golgi apparatus
4 or more stacked layers of thin, flat enclosed vesicles lying near one side of the nucleus
What is the only protein modified in the RER and not in the golgi apparatus?
Collagen
Protein enters and exits which sides of the Golgi apparatus
Protein enters the Covex (cis) side and exits on the concave (trans) side
Secretory vesicles or granules are formed from the
ER-Golgi system
Inactivated proteins
Proenzymes
Contained in secretory vesicles or granules
Lysosomes come from the
Golgi apparatus
Ribosomal subunits in prokaryotes vs eukaryotes
Prokaryotes: 30s and 50s (70s)
Eukaryotes: 40s and 60s (80s)
Suicide enzymes in the lysosomes
Hydrolases (40)
Functions of the lysosome
warfreak guy of the cell
Digests damaged cellular structures, food particles ingested by the cell and foreign bodies
Autolysis
Lysosomes are involved in which physiologic scenarios?
Regression of tissues (uterus after pregnancy, skeletal muscles follwoing inactivity, mammary glands after lactation)
Autolysis of cells (apoptosis and necrosis)
Wear and tear pigment that accumulates in lysosomes
Lipofuscin
Enzyme in lysosomes that dissolve bacterial membranes
Lysozyme
Enzyme in lysosomes that bind iron and other substances to prevent bacterial growth
Lysoferritin
Enzymes in lysosomes that activates hydrolases and inactivates bacterial metabolic systems
Acid with ph 5.0
Functions of peroxisomes
Formed by self-replication or budding from SER
Contains oxidase and catalase
Oxidises many poisons (eg alcohol)
Peaceful guy of the cell
Physically similar to lysosomes but with different functions
Peroxisomes
Types of filament or tubular structures
Actin and myosin
Microtubules
Lysosomes:hydrolases
Peroxisomes:?
Catalases and Oxidases (for detoxification)
Kartagener Syndrome
Situs inversus
Bronchiectasis
Infertility
Pathophysio: ciliary diskinesia
2 types of cell movement
Amoeboid and ciliary
2 types of proteins in the cell
Structural and Globular (Enzymes)
Degrades membrane associated proteins, not membrane bound.
Proteosomes
Drug of choice for S. aureus nasal carriers
Mupirocin
DOC for Toxic Shock Syndrome (TSS)
Clinda + Vancomycin
GI Hormone that increase during intake of coffee
Gastrin
Characterised by an episode of dramatic bradycardia following manipulation of extra-ocular muscles or dramatically raised intraocular pressure
Oculocardiac reflex
Other name for the oculocardiac reflex
Aschner phenomenon
% mass regeneration of the liver in 2-3 mos when removed
70%
DNA contains how many base pairs and genes?
3 billion base pairs and 200,000 genes
A chromosome is made up of
DNA + histone
Number of chromosome pairs in humans
23
Charges of DNA and Histone
DNA (-) charge
Histone (+) charge
Basic proteins of histones
Lysine and Arginine
The ETC in the mitochondria is found in the
Inner Mitochondrial Matrix
Number of complexes in the electron transport chain
I, II, III, IV
Complex V of the ETC
ATP synthase complex
In the ETC, oxygen is the final acceptor found in which complex?
Complex IV
MOA of Cyanide
ETC inhibitor (inhibits complex IV) - no generation of ATP
Hexokinase is created in the
Free floating ribosomes (glycolysis- cytoplasm)
Important molecular tag that tells the protein to go to the lysosome.
Mannose-6-phosphate
TB secretes ____ to prevent fusion of the lysosome and bacteria.
Sulfatides
Macrophages that fail to fuse with the TB bacteria are called
Langhan’s giant cell
2 Faces of the Golgi apparatus
Cis (convex) and Trans (concave)
Types of RNA
mRNA - massive
rRNA - rampant
tRNA - tiny
Nucleus without a nucleolus
Orphan annie
Why is the mitochondrial DNA only maternally derived?
Mitochondria of sperm dissociates during fertilization and what is left is the mitochondrial dna of the egg.
AUG codes for
methionine
Evolutionary explanation for the mitochondria
Anaerobic cell swallowing an aerobic cell (symbiosis)
Site of transcription and processing of rRNA
Nucleolus
The only substance modified in the RER and not the golgi appparatus
Collagen
Lysosomes and Peroxisomes come from which organelles?
Lysosome: Golgi
Peroxisome: SER
Wear and tear pigment that accumulates in the lysosomes
Lipofuscin
Cell filaments
Actin/Microfilaments
Intermediate filaments
Microtubules
Microtubules are from
Tubulin Dimers
Structures that are made up of Actin/Microfilaments
Microvilli, locomotion of macrophages, muscles, zonula adherens, zonula occludens
Structures that are made up of Intermediate filaments
keratin, neurofilaments, desmosomes, hemidesmosomes
2 Motor proteins found in microtubules
Kinesin and Dynein
Structures that are made up of microtubules
Flagella, Cilia, Centrioles, Mitotic spindle, intracellular vesicles
Disease with dynein missing in cilia and flagella
Kartagener Syndrome
Pathophysio of situs inversus in Kartagener’s
Defective primary cilia
Locomotion of cells
Ameboid movement, Ciliary movement, Flagellar movement
Cilia is found in which body structures
Fallopian tubes
Respiratory epithelium
Ameboid movement is exhibited by which cells
WBC, fibroblasts, germinal cells of the skin, fertilized embryo
In response to chemotactic substance
4 Junctional Complexes
Macula adherens (desmosomes) Zonula adherens (fascia adherens) Zonula occludens (tight junctions) Gap junctions
Structure, function and site of desmosomes
Structure: disk-shaped
Fxn: For firm intercellular adhesions
Sites: Epithelium “waterproofing”
Structure, function and site of fascia adherens
Ring-shaped
Increases surface area for contact
Sites: Intercalated discs of cardiac muscles
2 types of tight junctions
Leaky and tight
Structure, function and site of tight junctions
Reticular pattern
Divides cell into apical and basolateral side
Leaky: PCT, Jejunum
Tight: CD, terminal colon, BBB
Function and site of gap junctions
For intercellular communication
Cardiac and unitary smooth muscle
What is the functional unit of the gap junction?
Connexon
What do you call the movement of substances through the apical and basolateral side?
Transcellular transport
What do you call the movement of substances between cells through tight junctions?
Paracellular transport
The cell membrane divides the body into what compartments?
ECF and ICF Compartment
Majority of the cell membrane are made up of
Proteins (55%)
2 types of cell membrane proteins
Integral Proteins and Peripheral proteins
Components of the cell membrane
Proteins (55%) Phospholipids (25%) Cholesterol (13%) Other lipids (4%) Glycosylphosphatidylinositol (GPI) Carbs (3%)
The phospholipid bilayer is divided into
- Outer leaflet
2. Inner leaflet
What lipids are found in the outer and inner leaflet respectively?
Outer: Phosphatidylcholine, Sphingomyelin, Phosphatidylethanolamine
Inner: Phosphatidylinositol, Phosphatidylserine
Component of the cell membrane that mainly determines membrane fluidity and permeability to water soluble structures. (Most important component)
Cholesterol
Integral proteins vs. Peripheral
type of attachment and interaction
Integral: Tight attachments and Hydrophobic interactions
Peripheral: Loose and Electrostatic interactions
Which disease involves a mutation in the gene of Chromosome 7 that encodes for an ABC transporter called CFTR?
Cystic Fibrosis
2 types of endocytosis
Pinocytosis and Phagocytosis
Which type of endocytosis is used in proteins? For bacteria?
Pinocytosis: Proteins
Phagocytosis: Bacteria
Exocytosis is mediated by
SNARE Proteins
Endocytosis is mediated by
Clathrin
What is the 60-40-20 rule?
TBW 60% of Body weight
ICF 40%
ECF 20%
ECF is further subdivided into?
ECF 20%
Plasma 5%
Interstitial fluid 15%
Transcellular fluid 1L
Predominant Cation and Anion in the ECF and ICF
ECF: Na+, Cl-
ICF: K+, Ph-
Fluid intake on a normal day (ml/day)
2100 ml/day
Water Intake from metabolism (ml/day)
200
Total water intake (ml/day)
2300
Insensible losses from the skin/lungs (ml/day)
350 ml
Output from sweat and feces (ml/day)
100
Urine output (ml/day)
1400
Insensible loss from the skin during prolonged heavy exercise (ml/day)
350
Insensible water loss from the lungs during prolonged heavy exercise (ml/day)
650
Water loss from sweat during prolonged heavy exercise (ml/day)
5000
Water loss from feces during prolonged heavy exercise (ml/day)
100
Water loss from urine during prolonged heavy exercise (ml/day)
500
What is the principle of MACROSCOPIC ELECTRONEUTRALITY?
In each compartment, the total number of cations should equal the total number of anions.
What are the indicator molecules for TBW?
Deuterium oxide, Antipyrine
What are the indicator molecules for ECF?
Inulin, Mannitol
What is the indicator molecule for Plasma?
124 I-labeled Albumin
Osmolality vs Osmolarity
Osmolality = osmoles/kg of water Osmolarity = osmoles/liter of water (varies with temp)
Formula of osmolarity
Concentration x Number of dissociable particles
Estimate of plasma osmolarity can be obtained using which solutes
Na, glucose, urea
Formula for Plasma Osmolarity
2 x Plasma Na + (glucose/18) + (BUN/2.8)
Osmolar Gap
Measured osmolarity - Estimated osmolarity
Osmolar gap increases in
Alcohol intoxication and ethylene glycol poisoning (more solutes included)
Define osmosis
Movement of water from area of low concentration to high concentration across a semi-permeable membrane
Osmotic pressure is dependent on the
Number of molecules
Example of IMPERMEANT solute
Glucose (Effective Osmole)
Example of PERMEANT solute
Urea (Ineffective osmole)
Effective osmole used in the treatment of brain edema
Mannitol
Osmotic pressure from large molecules (proteins)
Oncotic pressure
Weight of the volume of a solution divided by weight of equal volume of distilled (pure) water
Specific gravity
Define Osmotic Coefficient/Reflection Coefficient
Number between one and zero that describes the ease by which a solute permeates a membrane
RC=1 no solute penetration
RC between 1-0 some penetration
RC = zero complete penetration
3 functions of the Na K ATPase Pump
- prevents cellular swelling
- contributes to RMP (-4mV)
- Helps secondary transport
What are the characteristics of active transport?
- Saturation: Tm occurs once all transporters are used
- Stereospecificty: recognizes D or L forms
- Competition: chemically-related solutes may compete.
Which is faster: simple or facilitated diffusion?
At low solute concentration: Facilitate > S
At high solute conc: Simple > F
“Usain bolt and ferrari”
“Usain bolt and speed limit”
Give examples of the transport mechanism mentioned below:
Simple Diffusion
Oxygen, Nitrogen, CO2, Alcohol, Lipid hormones, Anesthetic drugs
Give examples of the transport mechanism mentioned below:
Facilitated Diffusion
D-glucose transport to muscles and adipose tissues; Amino acid transport
Give examples of the transport mechanism mentioned below:
Primary Active Transport
Na-K-ATPase Pump
Ca-ATPase pump
H-K-ATPase Pump (Proton Pump) parietal cells
H-ATPase pump in intercalated cells (kidneys), multi-drug resistance transporters
Give examples of the transport mechanism mentioned below:
Secondary Active Transport
SGLT 1 in the Small Intestine SGLT 2 in the PCT NaK2Cl Ascending tubule Na Ca exchange in all cells Na H Change in PCT
Ca-ATPase pump in the cell membrane
PMCA
Ca-ATPase pump in the sarcoplasmic reticulum and endoplasmic reticulum
SERCA
Functions of the Na-K-ATPase pump
Prevents cellular swelling, contributes to RMP
Functional subunit by Na-K-ATPase pump inhibited by cardiac glycosides
Alpha subunit
In all epithelial cells, Na-K ATPase is found in the basolateral side except
Choroid plexus
Why do RBCs swell when chilled?
Decrease ATP synthesis –> Dec. Activity of Na-K-ATPase pump